Question

我有一个名为Flasher的WPF控件库项目中定义的WPF自定义控件。基本上，它是一个矩形，其Fill属性在两种颜色之间来回闪烁，就像控制台上闪烁的灯光一样。这是控件的模板，它位于库的Generic.xaml文件中：

<Style TargetType="{x:Type local:Flasher}">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type local:Flasher}">
                <Grid Name="LayoutRoot">
                    <Grid.Resources>
                        <Storyboard x:Key="FlashingStoryboard" AutoReverse="True" RepeatBehavior="Forever">
                            <ColorAnimationUsingKeyFrames BeginTime="00:00:00" 
                                                          Storyboard.TargetName="Flasher" 
                                                          Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
                                <LinearColorKeyFrame KeyTime="00:00:00.5" 
                                                     Value="{Binding Path=FlashColor, RelativeSource={RelativeSource AncestorType={x:Type local:Flasher}}}"/>
                            </ColorAnimationUsingKeyFrames>
                            <DoubleAnimation Duration="00:00:00.05" 
                                             From="0" To="10" 
                                             Storyboard.TargetName="FlasherBlur" 
                                             Storyboard.TargetProperty="Radius">
                            </DoubleAnimation>
                        </Storyboard>
                    </Grid.Resources>

                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="FlashStates">
                            <VisualState x:Name="Flashing" Storyboard="{DynamicResource ResourceKey=FlashingStoryboard}"/>
                            <VisualState x:Name="Stopped"/>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>

                    <Rectangle Fill="{TemplateBinding Fill}" 
                               Name="Flasher" 
                               Stroke="{TemplateBinding Stroke}" 
                               StrokeThickness="{TemplateBinding StrokeThickness}">
                        <Rectangle.Effect>
                            <BlurEffect x:Name="FlasherBlur" Radius="0"  />
                        </Rectangle.Effect>
                    </Rectangle>

                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

以下是控件的代码隐藏：

public partial class Flasher : Control {

    public static readonly DependencyProperty FillProperty =
        DependencyProperty.Register( "Fill", typeof( Brush ), typeof( Flasher),
                                     new FrameworkPropertyMetadata ( new SolidColorBrush( Colors.Silver), FrameworkPropertyMetadataOptions.AffectsRender ) );

    public static readonly DependencyProperty FlashColorProperty =
        DependencyProperty.Register( "FlashColor", typeof( Color ), typeof( Flasher ),
                                     new FrameworkPropertyMetadata( Colors.Transparent, FrameworkPropertyMetadataOptions.AffectsRender ) );

    public static readonly DependencyProperty FlashDurationProperty =
        DependencyProperty.Register( "FlashDuration", typeof( TimeSpan ), typeof( Flasher ), new FrameworkPropertyMetadata( TimeSpan.MinValue ) );

    public static readonly DependencyProperty StrokeProperty =
        DependencyProperty.Register( "Stroke", typeof( Brush ), typeof( Flasher ),
                                     new FrameworkPropertyMetadata( new SolidColorBrush( Colors.Silver ), FrameworkPropertyMetadataOptions.AffectsRender ) );

    public static readonly DependencyProperty StrokeThicknessProperty =
        DependencyProperty.Register( "StrokeThickness", typeof( double ), typeof( Flasher ),
                                     new FrameworkPropertyMetadata( 0.0, FrameworkPropertyMetadataOptions.AffectsRender ) );

    protected Application App {
        get { return Application.Current; }
    }

    protected ILog Log {
        get { return (ILog) App.Properties[ "Log" ]; }
    }

    public Brush Fill {
        get { return (Brush) GetValue( FillProperty ); }
        set { SetValue( FillProperty, value ); }
    }

    public Color FlashColor {
        get { return (Color) GetValue( FlashColorProperty ); }
        set { SetValue( FlashColorProperty, value ); }
    }

    public TimeSpan FlashDuration {
        get { return (TimeSpan) GetValue( FlashDurationProperty ); }
        set { SetValue( FlashDurationProperty, value ); }
    }

    private bool flashing = false;

    public bool IsFlashing {
        get { return flashing; }
        set {
            flashing = value;
            FrameworkElement grid = Template.FindName( "LayoutRoot", this ) as FrameworkElement;
            if ( flashing ) {
                if ( !VisualStateManager.GoToElementState( grid, "Flashing", true ) ) {
                    Log.Debug( "Flasher.cs:  Visual State Manager transition failed." );
                }
                if ( FlashDuration > TimeSpan.MinValue ) {
                    ThreadPool.QueueUserWorkItem( WaitForDuration, FlashDuration );
                }
            } else {
                if ( !VisualStateManager.GoToElementState( grid, "Stopped", true ) ) {
                    Log.Debug( "Flasher.cs:  Visual State Manager transition failed." );
                }
            }
        }
    }

    public Brush Stroke {
        get { return (Brush) GetValue( StrokeProperty ); }
        set { SetValue( StrokeProperty, value ); }
    }

    public double StrokeThickness {
        get { return (double) GetValue( StrokeThicknessProperty ); }
        set { SetValue( StrokeThicknessProperty, value ); }
    }

    public Flasher() : base() {}

    static Flasher() {
        DefaultStyleKeyProperty.OverrideMetadata( typeof( Flasher ), new FrameworkPropertyMetadata( typeof( Flasher ) ) );
    }

    private void TurnFlashingOff() {
        // Set IsFlashing to false
        IsFlashing = false;
    }

    private void WaitForDuration( object state ) {
        System.Threading.Thread.Sleep( (TimeSpan) state );

        Dispatcher.BeginInvoke( new Action( TurnFlashingOff ) );
    }
}

几个月前这一切都在运作，但现在还没有奏效。也就是说，我曾经看到闪光灯在我使用控件的窗口中设置的两种颜色之间改变了颜色。我在IsFlashing setter中设置了断点，我知道FindName调用正在返回Grid，我知道VisualStateManager调用工作，所以我不明白为什么我没有看到颜色变化。这让我非常困惑。

Plus Snoop似乎找不到有问题的Window。它不是我的应用程序的主窗口，而是一个无模式弹出窗口。本质上，带有问题的窗口来自Window，并使用以下代码创建和显示：

if ( Window == null ) {
    Window = new MyDialog();
    // Set some program-specific window properties that don't affect the display here . . .
    Window.Show();
}

所以Snoop毫无用处。

如果我发布的代码中没有明显的错误，那么我将不得不在我的代码中寻找其他问题。

感谢您提供任何帮助。

贝

Answer 1

我已经找到了问题的解决方案，将xaml代码与早期版本进行比较，直到我知道它正在运行。事实证明，在某些时候我已经将Visual State Manager的Flashing状态中的StoryBoard标记更改为DynamicResource;当它工作时，我将它设置为StaticResource。将其更改回StaticResource使其再次运行。

WPF关键帧动画正在运行但现在不行

1 个答案: